Controlling the ripening of bananas

ABSTRACT

To control the ripening of bananas in industrial banana processing, a group of bananas that have been harvested is obtained. The group of bananas has a plurality of bananas attached at a common crown. A first portion of the bananas of the group is placed inside of an ethylene-permeable container. A second portion of the bananas of the group is kept outside of the container. The group of bananas is exposed to ethylene gas, where the first and second portions of bananas are exposed to ethylene gas at approximately the same time to initiate ripening of the first and second portions of bananas at approximately the same time. The first and second portions of bananas are allowed to begin ripening. As the bananas ripen, the container regulates the flow of oxygen into the container and carbon dioxide out of the container such that the first portion of bananas inside of the container are exposed to lower oxygen levels and higher carbon dioxide levels than the second portion of bananas outside of the container, to reduce the ripening rate of the first portion of bananas compared to the second portion of bananas.

BACKGROUND

1. Field

The present application generally relates to the ripening of bananas, and, more particularly, to controlling the ripening of bananas from harvest to sale in industrial banana processing.

2. Related Art

Industrial farming of bananas generally occurs in tropical regions. Optimal banana production generally requires hot, wet conditions, as well as rich soil. Bananas mature about three months from the time of flowering. Green bananas typically contain about 20% starch and about 1% sugar. Bananas can begin the ripening process as soon as they are harvested. Ripe bananas take on a yellow color, and typically contain 66% sucrose, 14% fructose, and 20% glucose.

Bananas grow as a bunch having about 13-14 “hands” or rows of bananas. A typical hand has from about 14 to about 24 “fingers” (i.e., individual bananas) attached at a common crown. At the packing plant, hands are typically separated into smaller units refer to as clusters. Each cluster typically has about 3 to 10 individual bananas attached at a common crown. These clusters are the typical size found at retail and selling points in the market place in the U.S.

In industrial banana processing, bananas are harvested green. Industrial banana ripening usually involves exposing bananas to ethylene gas in an enclosed room at locations near destination markets. In most cases, bananas are placed in “ripening rooms” to initiate the ripening process prior to final shipment to the retail market. Ripening rooms expose bananas to ethylene gas at a temperature that typically ranges between 58 and 64° F. to facilitate uniform ripening. Ripening rooms have been described in, for example, U.S. Pat. Nos. 5,658,607, 5,041,298, 4,845,958, 4,824,685, and 4,764,389, each of which incorporated herein by reference in its entirety.

Conventional methods of banana ripening, however, provide for uniform ripening of all of the individual bananas in a hand or a cluster. This is particularly true for industrial ripening processes, in which large numbers of bananas are placed in a room and subjected to ethylene gas under similar or identical conditions. Consumers are thus forced to purchase a group of bananas, typically a cluster, that are at a single stage of ripening, and must consume the bananas before they become over-ripe.

SUMMARY

In one exemplary embodiment, to control the ripening of bananas in industrial banana processing, a group of bananas that have been harvested is obtained. The group of bananas has a plurality of bananas attached at a common crown. A first portion of the bananas of the group is placed inside of an ethylene-permeable container. A second portion of the bananas of the group is kept outside of the container. The group of bananas is exposed to ethylene gas, where the first and second portions of bananas are exposed to ethylene gas at approximately the same time to initiate ripening of the first and second portions of bananas at approximately the same time. The first and second portions of bananas are allowed to begin ripening. As the bananas ripen, the container regulates the flow of oxygen into the container and carbon dioxide out of the container such that the first portion of bananas inside of the container are exposed to lower oxygen levels and higher carbon dioxide levels than the second portion of bananas outside of the container, to reduce the ripening rate of the first portion of bananas compared to the second portion of bananas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary process of controlling the ripening of bananas;

FIG. 2 depicts a group of bananas attached at a common crown with a first portion of the group in a bag, and a second portion of the group outside the bag; and

FIG. 3 depicts two groups of bananas.

DETAILED DESCRIPTION

In order to provide a more thorough understanding of the present application, the following description sets forth numerous specific details, such as specific configurations, parameters, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure, but is intended to provide a better description of exemplary embodiments.

In one exemplary embodiment, with reference to FIG. 1, an exemplary process 100 of controlling the ripening of bananas from harvest to sale is depicted. In step 102, one or more groups of bananas are harvested. The term “group of banana” as used herein refers to any number of bananas attached at a common crown. For example, as described above, a bunch of bananas can be separated into hands, with each hand having about 14 to about 24 bananas attached at a common crown. A hand can be further separated into clusters, with each cluster having about 3 to about 10 bananas attached at a common crown.

In step 104, in each group of bananas, a first portion of the bananas is placed in a container, and a second portion of the bananas is kept outside the container. For example, with reference to FIG. 2, a group of bananas 200 is depicted with a first portion of bananas 202 placed inside of a bag 204, and a second portion of bananas 206 kept outside of bag 204. With reference to FIG. 3, two groups of bananas 200 are depicted with a first portion of bananas of each group of bananas 200 placed inside of a bag, and a second portion of bananas of each group of bananas 200 kept outside of the bag. In the present example, groups of bananas 200 are depicted as being hands of bananas. As noted above, however, a group of bananas 200 can include any number of bananas attached at a common crown.

With reference again to FIG. 2, the portion of group of bananas 200 placed inside of bag 204 (i.e., first portion of bananas 202) can include any number of bananas of group of bananas 200, provided that at least one banana is kept outside of bag 204. In one exemplary embodiment, the percent of bananas in first portion of bananas 202 can range between about 25 to about 75% of the total number of bananas in group of bananas 200. In another exemplary embodiment, first portion of bananas 202 includes at least one banana. In still another exemplary embodiment, first portion of bananas 202 includes at least about 25% of the total number of bananas in group of bananas 200. In yet another exemplary embodiment, first portion of bananas 202 includes about half of the total number of bananas in group of bananas 200.

Bag 204 can be constructed of any material known in the art that is permeable to ethylene. In one exemplary embodiment, bag 204 is formed from a plastic material. The plastic material can be made of any single resin or combination of a plurality of resins. Exemplary resins include, but are not limited to, low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, butadiene, polystyrene, polyester, or any combination of these material. In another exemplary embodiment, bag 204 can be made of polymers, or have added materials that modify the permeability of bag 204 to oxygen and carbon dioxide.

It should be recognized that different portions of bag 204 can be formed to have permeability to ethylene, oxygen and/or carbon dioxide. For example bag, 204 can be formed with some portions permeable to ethylene gas and other portions permeable to oxygen and carbon dioxide. The percent of the portions permeable to ethylene compared to the percent of the portions permeable to oxygen and carbon dioxide can determine the overall permeability characteristic of bag 204.

In one exemplary embodiment, bag 204 can have one or more perforations. Perforations can be of any size and shape. For example, perforations having a diameter between about 20 microns to about 12.5 mm can be used. The perforations can be visible to the naked eye or only under microscopic viewing.

The walls of bag 204 can have any thickness. In one exemplary embodiment, the walls of bag 204 have a thickness anywhere from about 0.00025 to 0.05 inches. In other exemplary embodiments, the thickness of the walls of bag 204 can be equal to or greater than about 0.00025, 0.0005, 0.00075, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.025, 0.03, 0.04, or 0.05 inches. In further exemplary embodiments, the thickness of the walls of bag 204 can be equal to or less than about 0.05, 0.04, 0.03, 0.025, 0.02, 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.003, 0.002, 0.001, 0.00075, 0.0005, or 0.00025 inches.

Bag 204 can be secured around the common crown of group of bananas 200 by any means known in the art. In one exemplary embodiment, the opening of bag 204 can simply be wrapped around the common crown. In another exemplary embodiment, the opening of bag 204 may be held around the common crown using a fastener, such as by a wire, cord, rubber band, and the like. Alternatively, bag 204 can be secured around the common crown using any adhesive known in the art. It should be recognized that bag 204 can be secured around a portion of the common crown, such as around half of the common crown, rather than around the entire common crown.

It should be recognized that various types of containers can be used in addition to bag 204. The container can be hard or soft. The container can also be one or more sheets of material that wraps around first portion of bananas 202. The container can be disposed tightly around or flush against first portion of bananas 202. Alternatively, the container may be disposed loosely around first portion of bananas 202.

With reference to FIG. 1, in step 106, the groups of bananas are shipped to one or more destination markets. With reference to FIG. 3, in the present exemplary embodiment, each group of bananas 200 is shipped with a first portion of bananas 202 in each group placed inside of bag 204, and a second portion of bananas 206 in each group kept outside of bag 204.

With reference again to FIG. 1, in step 108, the groups of bananas are exposed to ethylene gas to initiate ripening. With reference to FIG. 3, in the present exemplary embodiment, a group of bananas 200 is exposed to ethylene gas such that first portion of bananas 202 placed inside of bag 204 and second portion of bananas 206 kept out of bag 204 are exposed at the same time to the ethylene gas to initiate ripening.

Bananas naturally produce ethylene gas to initiate ripening. Ethylene gas produced by one banana triggers ripening of neighboring banana. In industrial banana production, where it is desirable for bananas to ripen uniformly, bananas are exposed to ethylene gas before the bananas naturally begin to produce ethylene gas, thus ensuring that bananas begin to ripen at approximately the same time. Very small quantities of ethylene gas are required to initiate ripening. Typically, as little as about 10 to about 100 ppm (parts per million) ethylene gas can initiate ripening.

With reference to FIG. 3, in the present exemplary embodiment, by exposing first portion of bananas 202 and second portion of bananas 206 to ethylene at the same time, all the bananas of group of bananas 202 begin ripening at the same time.

Groups of bananas 200 can be exposed to ethylene gas by any method known in the art. In one exemplary embodiment, groups of bananas 200 can be exposed to ethylene gas in a “ripening room.” Ripening rooms ensure the application of ethylene under airtight conditions to allow ethylene gas to remain around the bananas long enough to exert its effect of triggering ripening.

In general, there are two types of commercial ripening rooms: (1) conventional rooms and (2) pressurized or forced-air rooms. Conventional rooms are cold rooms with adequate air circulation to move the ethylene gas somewhat passively around and through the bananas. Pressurized rooms create a pressure gradient between rows of bananas. In such a configuration, ethylene gas is forced through the rows of bananas.

Groups of bananas 200 can be ripened in ripening rooms at various different temperature and relative humidity conditions. Ripening groups of bananas 200 can take place keeping a constant temperature during the entire cycle or varying temperatures during the cycle based on when the ripener needs the bananas to be ready to be shipped to the stores. For example, in one exemplary embodiment, the typical operating range of temperatures used during ripening cycles is about 58 to about 64° F., but a higher temperature, such as about 68° F., can sometimes be used.

In step 110, the groups of bananas are allowed to ripen. As the bananas ripen, they take in oxygen and release carbon dioxide. With reference to FIG. 2, bag 204 regulates the flow of oxygen and carbon dioxide in and out of bag 204. When oxygen levels inside bag 204 are reduced and/or carbon dioxide levels are increased (relative to concentrations in ambient air outside bag 204), respiration rates and metabolism of bananas slow down. Reduced metabolism results in reduced rates of all of the physiological and biochemical changes that occur during ripening, including loss of chlorophyll (appearing as a loss of green color and appearance of yellow color), conversion of starch to sugar, softening of banana, development of banana flavor and aroma. Thus, first portion of bananas 202 placed inside of bag 204 ripen at a slower rate than second portion of bananas 206 kept outside of bag 204, which results in extension of shelf life of first portion of bananas 202.

For example, in one exemplary embodiment, oxygen levels in bag 204 are reduced to between about 1 and about 10% and carbon dioxide levels are increased between about 1 and about 30% from levels in ambient air outside of bag 204. Thus, as depicted in FIG. 2, first portion of bananas 202 can remain green, while second portion 206 can ripen to a familiar fully-ripe yellow color.

In one exemplary embodiment, groups of bananas 200 are allowed to ripen in a ripening room under controlled temperature and relative humidity condition for a length of time (i.e., a ripening cycle). Typically, ripening cycles vary from 3 to 10 days. It should be recognized that groups of bananas 200 can be allowed to ripen for any length of time.

With reference to FIG. 1, it should be recognized that step 108 can be performed prior to step 106. Thus, the groups of bananas can be exposed to ethylene gas to initiate ripening before being shipped to destination markets. Additionally, the groups of bananas can be ripened during shipment (in transit). In one exemplary embodiment, the groups of bananas can be ripened in a portable ripening room during shipment. Containers and processes that can be used in banana ripening are described, for example, in U.S. Pat. No. 5,460,841.

In step 112, groups of bananas are shipped to retail and other selling points. With reference to FIG. 3, in the present exemplary embodiment, to maintain the different rates of ripening, the groups of bananas 200 are shipped with first portion 202 placed inside of bag 204, and second portion 206 kept outside of bag 204.

In step 114, groups of bananas are displayed for purchase by consumers. With reference to FIG. 3, in the present exemplary embodiment, groups of bananas 200 are displayed with first portion 202 placed inside of bag 204, and second portion 206 kept outside of bag 204. Thus, the consumer is provided with two groups of bananas at different ripening stages. The consumer can then decide the appropriate time to remove bag 204 from first portion 202 to allow the bananas in first portion 202 to complete the ripening process.

All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, or patent application were specifically and individually indicated to be so incorporated by reference. Although the foregoing embodiments have been described in some detail by way of illustration and example for purposes of clarity of understanding, it is readily apparent to those of ordinary skill in the art in light of the teachings of this application that certain changes and modifications may be made thereto. 

1. A method of controlling the ripening of bananas from harvest to sale in industrial banana processing, the method comprising: harvesting one or more groups of bananas, each group having a plurality of bananas attached at a common crown; placing a first portion of the bananas of each group inside of an ethylene-permeable bag, and keeping a second portion of the bananas of each group outside of the bag; shipping the one or more groups of bananas to one or more destination markets; exposing the one or more groups of bananas to ethylene gas, wherein the first and second portions of bananas of each group are exposed to ethylene gas at approximately the same time to initiate ripening at approximately the same time; allowing the one or more groups of bananas to ripen, wherein, as the bananas ripen, the first portion of bananas of each group placed inside of the bag are exposed to lower oxygen levels and higher carbon dioxide levels than the second portion of bananas of each group kept outside of the bag, resulting in a slower rate of ripening of the first portion of bananas compared to the second portion of bananas; shipping the one or more groups of bananas with the first portion of bananas of each group placed inside of the bag and the second portion of bananas of each group kept outside of the bag; and displaying the one or more groups of bananas to be purchased by a consumer with the first portion of bananas of each group placed inside of the bag and the second portion of bananas of each group kept outside of the bag to allow the purchaser to purchase a group of bananas with at least two portions of bananas at two different ripening stages.
 2. The method of claim 1, wherein the bag comprises a material selected from the group consisting of low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, butadiene, polystyrene, polyester, or any combination of these material.
 3. The method of claim 1, wherein the bag has one or more perforations.
 4. The method of claim 3, wherein each said perforation has a diameter greater than or equal to about 20 microns and less than or equal to about 12.5 mm.
 5. The method of claim 1, wherein the bag is closed by a fastener.
 6. The method of claim 5, wherein the fastener is selected from the group consisting of a tie, tape, rubber band, or cord.
 7. The method of claim 1, wherein the bag is placed loosely around the first portion of bananas.
 8. The method of claim 1, wherein the bag is placed tightly around the first portion of bananas.
 9. A method of controlling the ripening of bananas in industrial banana processing, the method comprising: obtaining a group of bananas that have been harvested, the group having a plurality of bananas attached at a common crown; placing a first portion of the bananas of the group inside of an ethylene-permeable container, and keeping a second portion of the bananas of the group outside of the container; exposing the group of bananas to ethylene gas, wherein the first and second portions of bananas are exposed to ethylene gas at approximately the same time to initiate ripening of the first and second portions of bananas at approximately the same time; and allowing the first and second portions of bananas to begin ripening, wherein the container regulates the flow of oxygen into the container and carbon dioxide out of the container such that the first portion of bananas inside of the container are exposed to lower oxygen levels and higher carbon dioxide levels than the second portion of bananas outside of the container, to reduce the ripening rate of the first portion of bananas compared to the second portion of bananas.
 10. The method of claim 9, wherein the container comprises a material selected from the group consisting of low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, butadiene, polystyrene, polyester, or any combination of these material.
 11. The method of claim 9, wherein at least a portion of the container comprises a polymer that modifies the permeability of container to oxygen and carbon dioxide.
 12. The method of claim 9, wherein the container has one or more perforations.
 13. The method of claim 11, wherein each said perforation has a diameter greater than or equal to about 20 microns and less than or equal to about 12.5 mm.
 14. The method of claim 9, wherein the container is a bag.
 15. The method of claim 9, wherein the bag is closed by a fastener.
 16. The method of claim 15, wherein the fastener is selected from the group consisting of a tie, tape, rubber band, and cord
 17. The method of claim 9, wherein the container is placed loosely around the first portion of bananas.
 18. The method of claim 9, wherein the container is placed tightly around the first portion of banana.
 19. A method of providing one or more groups of bananas in industrial banana processing, the method comprising: obtaining a group of bananas -from a supplier, the group having a plurality of bananas attached at a common crown, wherein a first portion of the bananas of the group is less ripe than a second portion of the bananas of the group, wherein the first portion of bananas has been placed inside of an ethylene-permeable container and the second portion of bananas has been kept outside of the container after being harvested, wherein the first and second portions of bananas have been exposed to ethylene gas at approximately the same time to initiate the ripening process of the first and second portions of bananas at approximately the same time, and wherein the first portion of bananas inside of the container has been exposed to lower oxygen levels and higher carbon dioxide levels than the second portion of bananas outside the container, to ripen the first portion of bananas at a slower rate than the second portion of bananas; and displaying the group of bananas to be purchased by the consumer, wherein the container is maintained over the first portion of bananas.
 20. The method of claim 19, wherein the container is a bag.
 21. The method of claim 20, wherein the bag comprises a material selected from the group consisting of low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, butadiene, polystyrene, polyester, or any combination of these material.
 22. The method of claim 20, wherein the bag has one or more perforations.
 23. The method of claim 22, wherein each perforation has a diameter greater than or equal to about 20 microns and less than or equal to about 12.5 mm.
 24. The method of claim 20, wherein the bag is closed by a fastener.
 25. The method of claim 24, wherein the fastener is selected from the group consisting of a tie, tape, cord, and rubber band.
 26. The method of claim 20, wherein the bag is placed loosely around the first portion of bananas.
 27. The method of claim 20, wherein the bag is placed tightly around the first portion of bananas.
 28. A system for ripening bananas, the system comprising: an ethylene-permeable bag placed over a first portion of bananas of a group of bananas attached at a common crown, wherein a second portion of bananas of the group are kept outside of the bag, wherein the bag permits the first and second portions of bananas to be exposed to ethylene gas at approximately the same time to initiate the ripening process of the first and second portions of bananas at approximately the same time, and wherein the bag controls the flow of oxygen and carbon dioxide to expose the first portion of bananas inside of the bag to lower oxygen levels and higher carbon dioxide levels than the second portion of bananas outside of the bag, to ripen the first portion of bananas at a slower rate than the second portion of bananas. 